I had a rather robust gentleman sit next to me on an MD-80 (the 2 seat side), who gobbled down 2 BigMac's, fries, and 2 apple pies before takeoff. An hour or so later the gasses began to fly. He looked me and apologized and blamed it on whats called CPAP therapy, where you apparently suck down air at nightime from a machine to help you breathe. I snagged his McDonalds bag from the seat pocket and said: I dont know anything about CPAP, but I do know the effects of BigMacs, Fries and Pies and thats what you have.